Aniline-black



UNITED STATES PATENT OFFICE.

JOHN BRACEWVELL, OF NORTH ADAMS, MASSACHUSETTS.

ANlLlNE-BLACK.

SPECIFICATION forming part of Letters Patent No. 409,822, dated August 27, 18 89.

Application filed February 15, 1889. Serial No. 299,984. (No specimens.)

To aZZ whom, it may concern:

Be it known that 1, JOHN BRACEWELL, of North Adams, in the county of Berkshire and State of Massachusetts, have invented a new and useful Improvement in Aniline-Black Color, of which the following is a specification.

My invention relates to the production of aniline-black color upon cloth; and it consists in a certain new and useful mode of compounding and developing the same, either alone or in connection with patterns printed thereon either as a resist or discharge, substantially as hereinafter described and claimed.

Heretofore aniline-black color has been produced upon cloth by the oxidation of the aniline when applied thereto; but its production has been attended with certain disadvantages when this oxidation was accomplished by the use of live steam or steam under pressure, because this process impaired the fiber of the cloth or made it tender where the aniline color came in contactwith it, and in consequence the goods when blotched or padded with the color were usually subjected to the wet steam or other aging process at a comparatively low temperature to avoid this difliculty. In this steam-aging process the steam is discharged into an open-air space and comes in contact with the goods in the shape of wet steam of such comparatively low temperature, and this aging process impairs the colors of the pigments used in the resist or discharge patterns printed thereon.

Another difiiculty in the employment of aniline-black arose from the practical impossibility of employing and developing it on goods upon which a pattern had been previously printed with a resist by the use of live steam or steam under pressure without tendering the goods, whereby the superior sharpness of outline in shade of the black edge against the pattermor vice versa, which is given by steaming the goods under pressure, was not produced and at the same time the strength of the fibers preserved. Again,

if the resist was mixed with pigment colors, the steaming of the latter to set them firmly and at the same time develop the anilin e-black was accompanied by this disadvantage of tendering the goods.

A third difficulty with the anilineblacks heretofore known was that after the aniline color was applied to thegoods and dried it oxidized so rapidly that there was not time afforded before oxidation to print on patterns with a discharge mixture, white or colored, in a certain economical and practical manner, it being necessary to employ the greatest care in drying the cloth and to hasten accident happened to the printing-machine or to the process of drying.

By my new mode of forming and compounding aniline-black color I am enabled to produce one which does not oxidize so rapidly in drying, and so allows time for a discharge 7o pattern to be printed thereon before oxidation, which can be developed by steam under pressure without tendering the goods and simultaneously with the setting of the colors of the discharge or resist thereby, and leaves the pigment colors in the resist or discharge of superior brilliancy, and which, with awhite discharge or resist, gives by this mode of development a superior sharpness to the outline of the colored pattern on the aniline ground in shade or line of both the color and ground against each other.

My invention consists in the discovery that when a certain proportion of ferro-cyanide to the aniline is used, much larger than has heretofore been employed in the compounding of aniline-black color, the oxidation of the aniline will be so retarded that the above effects are accomplished, and that under steam-pressure it will proceed in such a'mano ner as not to tender the fiber of the cloth. Moreover, when this proportion of ferro-cyanide is employed with the aniline and a proper proportion of chlorate of potash, the black produced by the oxidation of the aniline isof 5 superior quality, and the aniline color may be blotched, padded, or dyed entirely through the fiber of the cloth and developed perfectly, without injury to the fiber, by using steam under pressure-a result which I believe to be I00 new.

Heretofore so-called steam aniline colors have usually been printed on only one side of the cloth, and the tendering of the parts of it with which they came into contact when developed by steaming was not so material as it is when the cloth is saturated to any considerable depth by the color.

In order to form my aniline color I proceed as follows: I mix, cold, twelve gallons of the ferro-cyanide paste given below with four gallons of the solution of aniline-salt crystals given below, and add thereto four pints of aniline-oil, when the color is ready for use. The aniline-oil is added to neutralize any free acid which may exist in the aniline solution from the aniline salts, and it may be omitted if that solution contain no free acid. This preparation of the solution without free acid is of the utmost importance, as its presence in the color will cause it to act upon the fiber of the cloth under the steaming hereinafter described and destroy or seriously injure it. The ordinary salts of aniline of commerce contain free acid, and the use of the anilineoil is indispensable, unless the salts of aniline have been specially prepared so as to be free from acid. The presence of the free acid in the color when applied to the cloth will also prevent the fcrro-cyanide used in the proportions stated from retarding the oxidation of the aniline 011 the cloth, as before described. This aniline color may be padded into the cloth or printed thereon, as desired.

The ferro-cyanide paste-is formed as follows: Take forty-five gallons of water and dissolve in it seventy pounds of ferro-cyanideof-soda crystals and twenty-three and threefourths pounds of chlorate of potash. Add twenty pounds of corn-starch and boil till thickened, and cool. The corn-starch may be omitted or added in greater or less quantity as the printing, padding, or saturating of the cloth or yarns with the aniline color may re quire.

The solution of aniline salt is prepared as follows: Dissolve sixty pounds of aniline-salt crystals in ten gallons of hot water and cool. Instead of the salts of aniline, an equivalent amount of aniline-oil neutralized with hydrochloric acid may be employed. The anilineoil might be added to the solution of aniline salts, if preferred. If the oil be neutralized by the acid,'an excess of oil must be used to avoid the presence of free acid.

The proportions of the ferro-cyanide to the aniline salts in the above color may be varied, as I have only given the proportions I prefer to employ; but care should be taken that the proportion of the ferro-cyanide to the aniline shall never be less than eighty per cent. of the latter in any given quantity of color. Instead of ferro-cyanide of soda, the corresponding salt of potash or ammonia or other base may be employed, due allowance being made to preserve the equivalent proportions of the ferro-cyanide in strength under those forms. The insoluble chromates or chlorate of alumina might be employed instead of ferro-cyanide.

I employ in the above formula, which I prefer, about one hundred and eight parts of ferro-cyanide to each one hundred parts of aniline salts. When the proportion of ferrocyanide to aniline salts in the color exceeds eighty per cent. of the latter, I have found that the ferro-cyanide neutralizes or substantially neutralizes the aniline, forming a ferrocyanide of it, so that an injurious amount of chlorate of aniline cannot be formed in the color, and that a rapid process of the oxidation of the aniline is prevented when exposed to the action of steam under pressure, which rapid process substantially tenders or impairs the strength of the goods, if permitted.

To insure the complete neutralizationv of the aniline and the retarding of the formation of chlorate of aniline in the color, I prefer to employ the proportions I have given, and a greater amount may be employed, if preferred, as it is upon the neutralization of the aniline by the ferro-cyanide and the prevention thereby of the formation of an excess of chlorate of aniline in the color that the su perior qualities of my color depend.

'lheproportions of ferro-cyanide given and referred to above are of the normal strength of crystals, and if the desiccated form of ferro-cyanide of soda be employed, which has greater strength, a less amount may be employed-say, instead of a minimum of eighty pounds of the crystals, fifty pounds of the desiccated, or more, to each one hundred pounds of aniline salts, according to strength. A sure test of the amount of ferro-cyanide present, and one which determines whether it has substantially neutralized the aniline, is the capacity of the aniline to oxidize by the ordinaryprocess of aging the goods, as goods treated with my black color require steaming to oxidize and develop it. If it be found on trial that the aniline is oxidized by aging, then more ferro-cyanide must be added, for the salts or solution of it used must necessarily have been of less strength than what I have referred to in giving the proportions above stated, and it has not neutralized the aniline. Different preparations of ferrocyanide may vary in strengthas, for instance, when a solution of it is used instead of the salts-and in such cases the quantity must be ascertained by trial which should be employed.

The proportion of chlorate of potash used in the above color may also be varied with relation to that of the aniline, using between thirty and sixty-five pounds to each one hundred pounds of aniline salts, as its proportion is not so material, the formation of chlorate of aniline and consequent rapid OX- idation and development of the aniline color being retarded by the ferro-cyanide, as above explained, whether the chlorate of potash be present in greater or less degree.

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\Vhen, however, the steam under pressure is applied to the color and sets free the aniline from the ferro-cyanide, and the latter carries over the oxygen from the chlorate of potash to the aniline, (by means of its metallic properties,) sufficient chlorate of potash should be present to oxidize and develop the anilineblack in a superior manner, which I have as' certained by experiment to be at least thirty per cent, by weight, of the aniline salts used.

Ferri-cyanide of soda may be employed to form the described color in lieu of ferrocyanide, in which case the amount of chlorate of potash may be diminished in proportion, as none of it in that case will need to be taken up after the color is mixed to change ferro-cyanide into ferri-eyanide, and the amount of such diminution of the chlorate when ferri-eyanide is used will be about four and nine-tenths parts to every one hundred parts of ferro-cyanide.

If it is desired to produce a white pattern on the aniline-black ground, it maybe accomplished by printing the pattern on the cloth before the aniline-black is applied with are sist mixture, which is made up as follows: gum substitute, four pounds; acetate of soda, four pounds; water, eight pounds; dissolve and mix thoroughly in the water. If the resist is to be colored, mix with the acetate of soda albumen, either egg or blood, in place of the gum substitute, and a pigment of the desired color in sufficient quantity to produce the shade required, which can only be determined by experiment. The above-mew tioned proportion of gum substitute may be varied to make the resist thicker or thinner to suit the printing as well as the proportion of the acetate.

After the aniline coloris applied to the cloth it should be dried. It is then subjected to the action of steam underpressure in a steambox or continuous steamer to develop the aniline-black and fix the pigment colors of the resist pattern, if they are used. After steaming, soap and wash in the usual way and the process is completed.

If the above-described resist is to be used as a discharge, it is to be printed on the aniline-black ground in the desired pattern after drying, and in this case the drying had best be conducted on the steam-cans until the cloth is in a moist state and then completed in an atmosphere of about 50 Fahrenheit, as described in another application I have filed contemporaneously herewith. It will be found that the aniline color will not oxidize rapidly enough to prevent the discharge from acting effectively and producing the required pattern in white or colors, as the case may be, upon the aniline-black ground, and after drying the cloth with the aniline color thereon it may be kept for several days in a cool atmosphere before the discharge is printed thereon, so perfectly is the oxidation of the anilineblack retarded by its composition as described. The treatment of the cloth after the discharge is printed thereon and it is again dried is the same as above described for the resist.

The oxidation of my aniline-black rapidly by the high heat of the steam under pressure develops it so rapidly around the resist or discharge pattern that the action of the alkali of the latter cannot have any effect in or around the outline of its pattern upon the shade or conformation of it, and also prevents the formation of free acid, which affects the pigment colors and the alkali of the discharge or resist pattern in a large degree, impairing their brightness and tone, as is the case if moisture and comparatively slow aging were employed to oxidize ordinary aniline-black col- The patterns therefore appear upon the aniline-black ground, especially in whites, with a certainty and sharpness of outline which cannot be surpassed in clearness and boldness.

If neither a resist or discharge pattern is printed upon the cloth, the aniline-black will cover the same and form a plain black, and in this case as Well as the othersit will be found that the process or heat of the steam under pressure has not tendered the goods, even when so thoroughly saturated with the color as to develop on both sides alike, and I am therefore enabled to employ this fast steam aniline-black color for many purposes where it has not been heretofore successfully and certainly employed-such as yarns, plain cloths and umbrella-covers, &c., where the strength of the goods and durability of the color are of the highest importance.

What I claim as new and of my invention 1s- 1. The aniline-black color formed of ferrocyanide of soda, chlorate of potash, and aniline salts prepared for use in such a manner as to be free from the presence of hydrochloric acid, substantially as set forth-that is to say, with the ferro-cyanide in amount sufficient to take up the aniline and prevent the formation of chlorate of aniline in injurious quantity in the color, substantially as described.

2. The aniline-black color formed of ferrocyanide of soda, chlorate of potash, and aniline salts prepared for use in such .a manner as to be free from the presence of hydrochloric acid, substantially as set forth-that is to say, with the ferro-cyanide in quantity sufficient to take up the aniline and the chlorate in quantity not less than thirty-five per cent. of that of the aniline,substantially as described.

JOHN BRAOEVELL.

Vitnesses:

DAVID HALL RICE, N. P. OOKINGTON.

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